Mixtures of unsaturated polyesters and monomeric ethylene compounds copolymerizable therewith containing cobalt salts and a member of the group of arsines, stibenes, andphosphines



3,274,291 MIXTURES F UNSATURATED POLYESTERS AND MONOMERIC ETHYLENE COMPOUNDS CO- POLYMERIZABLE THEREWITH CONTAHWHNG COBALT SALTS AND A MEMBER OF THE GROUP OF ARSINES, STIBENES, AND PHOSHHINES Karl Raichle, Kreteld-Urdingen, and Hans Rudolph,

Krefeld-Bockum, Germany, assignors to Farbenfahriken Bayer Aktiengesellschaft, Leverkusen, Germany, a German corporation No Drawing. Filed June 8, 1962, Ser. No. 200,947 Claims priority, application Germany, July 5, 1961, F 34,347 10 Claims. (Cl. 260-863) The present invention is concerned with new mixtures of unsaturated polyesters and monomeric ethylene compounds copolymerizable therewith which are hardenable at room temperature to give non-green synthetic resins.

It is known to accelerate polymerization reactions, initiated by radical-forming organic peroxides, by the addition of small, catalytically-eifective amounts, that is to say: in general from about 0.005 to about 0.1 percent by weight, related to the cobalt content, of cobalt compounds. For this purpose, it is preferred to use the cobalt salts of higher carboxylic acids, such as the naphthenate, resinate, linoleate or octoate, but soluble cobalt salts of partially esterified polycarboxylic acids, such as the monoisooctyl rnaleate, as well as compounds with chelate-like bound cobalt, such as cobalt acetyl-acetonate and cobalt acetoacetic ester, are also suitable.

The acceleration is, when ketone peroxides, such as the different methyl ethyl ketone, peroxides, methyl isobutyl ketone peroxides, as well as cyclohexanone peroxides, and possibly also mixtures with other peroxides, such as lauroyl peroxide, benzoyl peroxide, cumol hydroperoxide, 1,2,3,4-tetrahydronaphthalene hydroperoxide, tert.-butyl hydroperoxide, di-tert.-butyl peroxide and tert.-butyl perbenzoate, are used, so outstanding that polymerizations are even initiated at room temperature and are terminated without the application of heat.

Because of this advantage, peroxides of the type mentioned are used, to a large extent, in combination with cobalt accelerators, for the hardening of mixtures of unsaturated polyesters, which contain the residues of a,,8-unsaturated dicarboxylic acids, and co-polymerizable monomeric ethylene compounds, said polyesters being commonly called, and also so-called in the following, polyester resins. Since, however, the peroxides, as a rule, oxidize the initially divalent cobalt to the dark green coloured trivalent cobalt, there is frequently produced the known and feared disadvantage that the hardened products are coloured green, this being the more so the lower lies the hardening temperature, i.e. particularly when hardening is carried out at room temperature and a large surface area is present in comparison with the volume, so that the heat liberated during the hardening can be conducted away or can radiate off, as is, for example, the case in the use of polyester resins in lacquer technology. The green coloration is especially disturbing when bright underlayers are to be coated with polyester resins.

Practically only resins of unsaturated polyesters with high acid numbers (above about 50) and a high content of cap-unsaturated dicarboxylic acid residues are free arena 3,274,291 Patented Sept. 20, 1966 ice from this fault. However, such resins become cloudy on storage or even separate out as crystals. Such resins are frequently blended with resins of polyesters with a lower content of u,fi-unsaturated dicarboxylic acids in order to render the hardened product elastic but these, however, again become green.

In order to prevent the mentioned green coloration, it

has already been suggested to add dipentene, lactic acid,

zinc octoate or phosphorous acid or its esters, to the polyester resins. Large numbers of other preferably acidic or acid-forming additives, as Well as salts of such acids, such as also cobalt salts, which are soluble in polyester resins, also act in the same way. Such cobalt salts may be used in place of the previously mentioned cobalt accelerators. By Way of example, there may be mentioned phosphoric acid, pyrophosphoric acid, phosphorous acid, phosphonic acids, such as styryl phosphonic acid and n-heptylphosphonic acid, phosphinic acids, such as diphenyl phosphinic acid and diisobutylphosphinic acid, phosphonous acids, such as phenyl phosphonous acid and heptyl phosphonous acid, amides or partial esters of these acids, such as phosphoric acid-tris-isobutyl-amide, phosphoric acid-tris-isomayl-amide, di-n -butyl phosphoric acid, mono-n-butyl-phosphoric acid and mono-n-octyl phosphorous acid, phosphorus pentoxide, phosphrus trioxide, phosphorus pentachloride, phosphorus trichloride, phosphorus oxychloride, phosphorus oxybromide and ester halides of acids of phosphorus, such as monobutyl phosphoric acid dichloride and diisobutyl phosphoric acid monochloride; furthermore, corresponding thiophosphorus compounds, such as phosphorus thiochloride, thiophosphoric acid amides, for example, thiophosphoric acid-tris-isobutylamide and thiophosphoric acid-tris-isoamyl amide, and thiophosphoric acid ester halides, such as diethylthiophosphoric acid-chloride and monopropylthiophosphoric acid-dichloride, as well as soluble sulphonic acids, such as di-tert.-butyl-naphthalene-sulphonic acid, and also formic acid, oxalic acid, malonic acid, malic acid, tartaric acid and citric acid, as well as partial esters of the mentioned polybasic carboxylic acids, such as malonic, malic, tartaric and citric acid mono methyl and ethyl ester, and derivatives forming such acids, such as acid chlorides and bromides, for example, oxalyl chloride and bromide.

These compounds which are capable to prevent the green coloration of the hardened products may, if desired, be present in amounts from about 0.001 to about 1.0 percent by weight related to the hardenable mixture.

The removal of the green coloration by such additions is, however, always tied up with a very disturbing reduction of the reactivity of the resins, as can easily be determined by, for example, measurement of the gel time, i.e. of the time which passes after the admixing of the peroxide to the resin, which already contains cobalt accelerators, to the gel formation. Especially long gel times are produced when there are used as accelerators the above-mentioned soluble cobalt salts of the acids which are effective against the green colour formation or When polyester resins which do not give green coloured hardened products, amongst which are also to be considered the mentioned resins with high acid number, are stored after admixture with cobalt accelerators.

Since the peroxides react with the cobalt accelerators explosively when in an undiluted state and, when insufficiently diluted, still react with decrepitation, the final user is preferably supplied, for reasons of safety, with resins which already contain cobalt accelerators to which only peroxides still have to be added in order to harden them. In this case, it is, however, unavoidable that resins which have been stored for more or less long periods of time, i.e. resins with very different reactivity produced. Losses of reactivity, however, often result not only in a delay of the hardening but even in the formation of an incompletely hardened product. In any case, considerable working-up difiiculties can occur so that, in particular, a modern rationalization working upon an assembly line, is no longer possible.

We have found that the mentioned losses of reactivity of polyester resins yielding non-green colored hardened products can be overcome by the addition of phosphines, arsines and/or stibines.

If is surprising that colorations do not occur again, since such additives, which are effective as promoters, result in a strengthening of the coloration in the case of resins forming green-colored hardened products.

According to US. patent specification No. 2,520,601, phosphines of the general formula:

wherein R is an alkyl or aryl radical and R and R are hydrogen atoms or alkyl radicals, accelerate the polymerization of polyester resins 'by acyl peroxides, such as benzoyl peroxide, lauroyl peroxide, diacetyl peroxide and acetyl-benzoyl peroxide, in such a manner that it can be carried out without the application of heat. However, quite apart from the fact that the acceleration effect of the phosphines in this case is debatable, as follows from a later publication by Homer (Annalen, 591, 108/ 195 our own experiments (cf. following table) show that at least the hardening of polyester resins initiated by ketone peroxides is certainly not accelerated by any means as much as to the extent achieved by cobalt compounds.

4 eral, sufficient to add 0.01 to 1%, referred to the resin solution. Amounts considerably exceeding this are to be avoided since overdosage can also cause colorations of the hardened products.

The unsaturated polyesters mentioned above are well known in the art and are described, for example, in US. Patent No. 2,931,784 to Raymond. They are generally prepared by the reaction of an a-unsaturated, nip-polycarboxylic acid or anhydride with a glycol. Typical examples o-f polybasic acids and anhydrides which may be used to prepare the unsaturated polyesters are maleic, fumaric, itacoinic, aconitic, mesaconic, citraconic, ethyl maleic, dichloro maleic acid or anhydride. The foregoing polybasic acids or anhydrides may be esterified with such .dihydric alcohols as ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,2- or 1,3-dipropylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, l,2-butylene glycol, neopentyl glycol, 1,3-pentanediol, 1,5-pentanediol. The polyesters may be modified by adding to the esterification reaction other modifying polybasic acids or anhydrides such as, for example, phthalic, terephthalic, isophthalic, succinic, adipic, suberic, acelaic, sebacic and 3,6-endomethylene tetrahydrophthalic acids and whydrides or their derivatives, such as the halogenated substituted derivatives of the aforementioned acids or anhydrides, examples of which are tetrachlorophthalic and hexachloroendomethylene-tetrahydrophthalic acid. If desired, little amounts of monobasic acids or/and monohydric alcohols, such as propionic acid, butyric acid, saturated and unsaturated higher fatty acids, for instance, palmitic acid, stearic acid, linoleic acid, soya bean oil acid, ricinenic acid and so on, and benzoic acid, as well as amyl alcohol and higher aliphatic alcohols, cyclohexanol, methyl cyclohexanol, may also be used for modifying the polyesters.

A special group of unsaturated polyesters the solutions of which in monomeric ethylene compounds, such as strene, may be used as air-drying and hardening lacquers are obtained by poly-condensing cap-unsaturated dicarboxylic acids as mentioned above with hydroxy com- Pcrcent peroxide in polyester s u on solution Percent accelerator in polyester Hardened product 24 hours after gelling Gel time 1 2.0 n11)ethyl ethyl ketone peroxide 1 For the determination of the gel time, 10 g. test samples were used in test tubes which, for the removal of the heat of reaction, were placed in a water bath maintained at 20 C. by means of a thermostat.

Therefore, the additional increase in reactivity induced by the addition, according to the invention, of phosphines, arsincs and stibines in the case of hardenings initiated by the cobalt accelerator/ketone peroxide system and taking place at room temperature, is all the more surprising.

According to the present invention, there are usedcompounds whioh are preferably of low volatility and are as insensitive as possible to air. Examples therefore are triphenyl phosphine, tritolyl phosphine, diphenyl phosphine, dibenzyl phosphine, dioctyl phosphine, phenyl dimethyl phosphine, diethyl naphthyl phosphine, tributyl phosphine, trioctyl phosphine, tris-(hydroxyethyl)-phosphine, methylene-bis-diphenyl phosphine, tricyolopentyl phosphine, triphenyl arsine, tribenzyl arsine, trioctyl arsine, trip henyl stibine, tridiphenyl stibine, trinaphthyl stibine and tritolyl sti-bine.

The mentioned promoters are preferably added to the polyester resin at room temperature or at a slightly elevated temperature. If the compounds are introduced at room temperature, then they are frequently only completely effective after several days; however, if they are admixed at an elevated temperature, then they immediately reach their full effect.

In order to remove the loss of reactivity, it is, in genpounds containing Bq-ethylenically unsaturated ether groups as described, for example, in US. Patent No. 2,852,482 to Maker and British patent specification No. 810,222 to Farbenfabriken Bayer Aktiengesellschaft. Examples of such ether alcohols are allyl, methallyl, ethallyl, chlorallyl, crotyl and cinnamyl ethers of dior polyhydric alcohols, such as glycols, glycerine, trimethylolethane, -propane, -butane, pentaerithritol etc., for instance, the glycerol allylethers, trimethylolethane monomethallyl ether, trimethylolpropane monoand diallyl ether, pentaerithritol monoand triallyl ether, and glycidally-l ether. The Bq-unsaturated ether radical may also be introduced into the polyester as an ether acid such as allyloxysuccinic acid and ,S-allyloxypropionic acid.

The acid number of the unsaturated polyesters may amount, in general, from about 5 to about 80.

The monomeric ethylene compounds copolymerizable with the unsaturated polyesters Which maybe used for preparing the unsaturated polyester resins mentioned above are likewise well known in the art and are also described, for example, in the aforementioned Raymond Patent No. 2,931,784. Typical representatives of these compounds are, for example, styrene, vinylt-oluene, halogenated styrenes and vinyltoluenes, divinyl benzene, vinyl esters, such as vinylacetate, acrylic and methacrylic acids and their derivatives, aliphatic and aromatic allyl, diallyl and triallyl compounds, such as esters and ethers thereof, for instance, allyl acetate, diallyl phthalate, triallyl 6 hydride and 828 parts phtha-lic anhydride with 738 parts butane-1,3-dio1, wit-h the addition of 0.5 part hydroquinone, is dissolved in an equal number of parts of styrene. The thus obtained polyester resin is, according phosphate, diallyl ether etc. 5 to the experiments set out in Table I, hardened in its The ratio of unsaturated polyester to monomeric ethyloriginal form, in the presence of promoters, in the presene compound may, in general, amount from about 10 ence of sub-stances for the prevention of green coloration, to 90 to about 90 to 10. as Well as, according to the invention, in the presence of In order to increase the storage stability, the polyester both additives. By the admixture of a cob-alt accelerator resin can contain known inhibitors, such as p-benzo- 10 thereto, a cobalt content of 0.016% is adjusted and the quinone, 2,5-di-tert.-butyl-quinone, hydroquinone, tert.- hardening subsequently initiated after different periods butyl-pyrocatechol, 3-methyl-pyrocatecho1 and 4-ethylof storage (see Table I, column 5) by the stirring in of pyrocatechol, as well as copper compounds, such as copperoxide. per naphthenate. If the catalyzed resin, to which has been added, in The parts given in the following examples are parts known manner, 1.4% of a 10% paraflin solution in by weight. The percentages of the additives refer to the toluene for the achievement of a surface drying, is put, polyester resins. Under the given gel times, there is to with the help of a spray gun, on to bleached maple, then, be understood the times which pass between the admixindependently of the period of storage, not only the origing of a peroxide to the coha'lt accelerator-containing inal resin but also the resin modified according to the inresin and the gel formation. For the determination of vention give dry iilms after 2-3 hours which, in the case the gel time and for the assessment of the colour of the of the original resin, are green coloured whereas, in the hardened products, there are used 10 g. samples in test case of the resin modified according to the invention, are tubes which are kept in a water bath, maintained at 20 colourless. The resin which is only modified by a pro- C. by means of a thermostat, for the removal of the heat motor admittedly dries within 2 hours but the iilms obof reaction, until hardening has taken place, tained are even more strongly coloured than those of the EXAMPLE 1 original resin. The resin which is only modified by :an

additive preventing the green coloration gives, upon test- An unsaturated polyester with an acid number of 44 ing, films which dry with a delay, depending on the produced by the condensation of 235 parts m-aleic anperiod of storage, which often amounts to several hours.

Table I Addition for the inhibition of Cobalt Gel Colour of hardened greening Promoter accelerator Peroxide Storage (time) product Naphthenate.. 2% cyclohexanone peroxide.-.. 0 Green.

24 hours. 32 Do. 14 days.- 31 Do. 28 days.. 33 Do.

Octoate 2% methyl ethyl ketone per- 28 Green.

oxide. 24 hours. 30 Do. 14 days.. 29 Do. 28 days.. 30 Do.

Naphthenate.. 1% cyclohexanone peroxide 60 Green.

+%1tetralinhydroperoxide. 24 hours. 65 Do. 14 days. 65 Do. 28 days.. 65 Do.

0.18% triphenyl phosphine Naphthenate 1% eyclohexanone peroxide 0 Dark green.

+1% tetralinhydroperoxide. 24 hours. 37 Do. 14 days.. 40 Do. 28 days.. 46 Do.

0.18% triphenyl phosphine Naphthenate.. 2% cyolohexanone peroxide..... 0 22 Dark green.

24 hours. 21 Do. 14 days.. 23 Do. 28 days.. 24 Do.

0.41% triphenyl arsine Oetoate 2% methyl ethyl ketone per- 0 23 Dark green.

oxide. 24 hours. 24 Do. 14 days.. 24 Do. 28 days.. 25 Do.

0.45% triphenyl stibiue 0c0tate. 2% methyl ethyl ketone 0 23 Dark green.

peroxide. 24 hours. 23 Do. 14 days.. 25 Do. 28 days.. 24 Do.

0.012% phosphoric acid 2 Naphthenate-. 2% oyclohexanone peroxide..." 0 Bright pink.

24 hours Do. 14 days.. Do. 28 days.. Do.

0.012% phosphoric acid 2 0.18% triphenyl phosphine Naphthenate.- 2% cyclohexanone peroxide.-.. 0 30 Bright pink.

24 hours 32 D0. 14 days.. 31 Do. 28 days 33 Do.

0.014% phosphoric pentoxide Naphthenate.. 2% eyclohexanone peroxide.... 0 40 Bright pink.

24 hours 100 Do. 14 days Do. 28 days-- 120 Do.

di-n-butyl ester up to a cobalt concentration of 0.016%. 60

Table IContinued Addition for the inhibition of Cobalt Gel Colour of hardened greening Promoter accelerator Peroxide Storage (time) product 0.014% phosphoric pentoxide 0.18% triphenyl phosphine N aphtheuate.. 2% cyclohexanone peroxide. 8-1;--- 27 Almgst colourless.

4 ours. o. 14 days.- 30 Do. 28 days" 32 Bright pink.

0.018% tartaric acid 3 Naphthenatc.. 2% cyclohexanone peroxide..." 0 Bright pink.

24 hours. 64 Do. 14 days 75 Do. 28 days 90 Do.

0.018% tartaric acid a 0.18% triphenyl phosphine Naphthenate. 2% cyclohexanone peroxide. 01H--." 28 Almlgst colourless.

' 2 ours. 27 0.

14 days. 30 Bright pink. 28 days 30 Do.

0'035% maleic acid 2 Naphthenate.. 2% cyclohexanone peroxide.-. 0 47 Bright pink.

24 hours. Do. 14 days 70 Do. 28 days. 100 D0.

0.035% malcic acid 2 0.18% triphenyl phosphine Naphthenate.- 2% cyclohexanoue peroxide-.. 0 34 Bright yellow, al-

most colourless. 24 hours. 35 Do. 14 days. 35 Bright pink. 28 days" 35 Do.

0.035% maleic acid 2 Naphthenateu 1% cyclohexanone peroxide 0 75 Bright pink.

+1% tetralin hydroperox- 24 hours. 90 Do. ide. 14 days.- 120 D0. 28 days.. 120 Do.

0.035% maleic acid 2 0.18% triphenyl phosphine Naphthenate. 1% cyclohexanone peroxide 0- Bright pink.

+1% tetralin hydroperox- 24 hours. D0. ido. 14 days Do. 28 days 75 Do.

0.07% formic acid 1 Naphthenate.. 2% cyclohexanone peroxide.. 0 59 Bright pink.

24 hours. 75 Do. 14 days 120 Do. 28 days.. 120 Do.

0.07% formic acid 1 0.18% triphenyl phosphinc Naphthenate.. 2% cyelohexanone peroxide--- 0 34 Almost colourless.

24 hours. 35 Do. 14 days. 32 Do. 28 days.. 31 Do.

0.013% phosphorous acid Octoate 2% methyl ethyl ketone 0 43 Bright pink.

peroxide. 24 hours. 55 D0. 14 days. Do. 38 days" D0.

0.013% phosphorous acid 0.18% triphenyl phosphine Octoate 2% methyl ethyl ketone 0 29 Almost colourless.

peroxide. 24 hours. 30 Bright pink.

14 days 28 D0. 28 days 32 Do.

0.013% phosphorous acid 0.45% triphenyl stibine Octoate 2% methyl ethyl ketone 0 32 Almost colourless peroxide. 24 hours. 32 Do. 14 days. 34 Do. 28 days- 35 Bright pink.

0.013% phosphorous acid 0.41% tripheuyl arsine Octoate 2% methyl ethyl ketone 0 31 Bright yellow.

peroxide. 24 hours- 35 Almost colourless.

14 days. 34 Do. 28 days 35 Bright pink.

1 Added to the polyester resin. 3 Added to the unsaturated polyester at 170 C. 2 Added to the unsaturated polyester at C. 4 Added to the polyester resin at 40 0.

EXAMPLE 2 thenate, corresponding to 0.016% cob-alt, is added to the so-obtainecl polyester resin. 'If the hardening is initiated by the admixing of 4% of a 50% solution of methyl ethyl ketone peroxide in dimethyl phthalate, then the polyester resin hardens after 30 minutes with the formation of a green coloured hardened product. However, if 0.18% triphenyl phosphine is admixed with the 'same cobalt-containing polyester resin at 30-40 C. and the hardening initiated by the addition of 4% of a mix- 65 ture which contains, besides 49.65% methyl ethyl ketone peroxide and 49.65 dimethyl phth-alate, also 0.3%

To the polyester resin described in Example 1, there is added, as accelerator, the cobalt salt of phosphoric acid The gel time determined after the stirring in of 2.0% cyclohexanon'e peroxide amounts to 70-8O minutes; the hardened product obtained is almost colourless to slightly pink coloured. If, up to the time of hardening of the resin, the resin contains a concentration of 0.2% of triphenyl phosphine introduced at 40 C., then there is admittedly also obtained an almost colour-less hardened product but the hardening time amounts to only 30 mjm phosphoric acid mono-mbutylester and 0.4% phosphoric utes. If the cobalt accelerator-containing resin modified P ester for the PreVennQn green Coloraby tpiphenyl phosphine is hardened fi t ft days 70 tron, then an almost colourless to light pink coloured storage, then the same favourable result is obtained. hardened 'PFQ 15 obtallled Wlth an unalterefi 1'5"" F If the addition of the triphenyl phosphine is omitted,

EXAMPLE 3 then the hardening carried out in the presence of the partial esters of phosphoric acid admittedly also leads The unsaturated polyester described in Example 1 is to almost colourless to light pink coloured hardened dissolved 50% in vinyl toluene and 0.15% cobalt naph- 75 products but the gel time is increased by about 50%.

9 EXAMPLE 4 An unsaturated polyester with an acid number of 27 produced by the condensation of 340 parts maleic anhydride, 857 parts phthalic an-hydride and 337 parts adipic acid with 900 parts propane-1,2-diol, with the addition of 0.29 part hydroquinone, is dissolved in the same number of parts of styrene and the resin obtained adjusted to a cobalt content of 0.015% by the addition of cobalt naphthenate. The hardening takes place after storage periods of diiferent lengths, in each case with the addition of 2.0% cyclohexanone peroxide. In Table II are given the gel times and the colours of the hardened products for the unmodified polyester resin, for the resin admixed with malonic acid monoethyl ester -for the prevention of green coloration, as well as for the resin admixed with this semi-ester and, in addition, with tri-pheny-l phosphine according to the invention, in dependance upon the period of storage of the cobalt accelerator-containing 1 Mixed with the polyester resin. 2 Mixed with the polyester resin at 70 0. immediately after production.

EXAMPLE 5 The data given in the following Table III show that, by the use according to the invention of phosphine, arsines and stibines, the gel time of a resin, which naturally does not become green, becomes shortened and substantially independent of the storage period of the cobalt accelerator-containing lacquer, without green colourings being caused by these additions. The experiments are carried out with a 47% styrene solution of an unsaturated polyester which has been obtained by the condensation of 282 parts maleic anhydride and 357 parts phthalic anhydride with 398 parts propane-1,2-dio1, with the addi- Table III Storage Gel Colourof hardened Promoter time time product (min.)

13 Bright pink. 24 hours. 15 D0. 14 days" 28 Do. 28 days Do.

' 0.11% tripheuyl phosphine O 10 Almost colourless.

24 hours. 12 Bright pink. 14 days" 12 Do. 28 days 14 Do.

0.00% penyl dimethyl phos- 0 10 Almost colourless.

ph me 1 24 hours. 10 Bright pink.

14 days 11 Do. 28 days- 14 Do.

0.45% tridiphenyl stibine 0 10 Bright pink.

24hours. 10 Do. 14 days. 13 Do. 28 days 15 Do.

0.12% tri-n-butyl phosphine 0 11 Bright pink.

24 hours 11 Do. 14 days 13 D0. 28 days 15 Do.

0.28% triphenyl arsine 0 10 Bright pink.

24 hours 11 D0. 14 days" 14 Do. 28 days. 14 Do.

tion of 0.13 part hydroquinone, up to an acid number of 56. Not only the unmodified resin, but also the resin modified according to the invention, contain 0.016% cobalt as naphthenate and, after different periods of storage, are hardened by the admixture of 2.0% cyclohexanone peroxide.

1 Mixed with the polyester resin at 2535 0.

EXAMPLE 6 An unsaturated polyester with an acid number of 32, obtained by the condensation of 490 parts maleic anhydride and 740 parts phthalic anhydride with 610 parts glycol and 535 parts trimethylol propane diallyl ether with the addition of 0.22 part hydroquinone, are dissolved 45% in styrene and the resin obtained adjusted to -a cobalt content of 0.016% by the addition of cobalt naphthenate. Table IV gives the gel time measured after the admixing of 2.0% cyclohexanone peroxide, as well as the colours of the hardened products for the unmodified polyester resin and of the polyester resin modified by partial esters of phosphoric acid, as well as of the polyester resin modified with such esters and, additionally, according to the invention, with triphenyl phosphine. The dataare given in dependence upon the length of storage time at 40 C. of the cobalt accelerator-containing resins.

Table IV Triphenyl Storage Gel Colour oi Additive for preventing the greening phosphine, time time hardened percent (min.) product 0 12 Green. 1 day 12 D0. 3 days- 11 Do. 7 days- 12 Do.

0.013% phosphoric acid 2 motion-butyl 0 16 Bright pink.

ester+0.017% phosphoric acid 1 di-n- 1 day 21 Do. butyl ester. 3 days. 30 Do. 7 days 34 Do.

0.013% phosphoric acid 2 mono-n-butyl O. 16 0 11 Bright pink.

ester+0.017% phosphoric acid di-n- 1 day 13 Do. butyl ester. 3 days. 13 Do. 7 days 14 D0.

1 Mixed with the polyester resin at 40 C. 2 Mixed with the polyester resin.

1 1 EXAMPLE 7 The 50% styrene solution of an unsaturated polyester with an acid number of 44, obtained by the condensation of 447 parts maleic anhydride and 552 parts phthalic anhydri de with 647 parts propane-l,2-idiol, with the addition of 0.20 part hydroquinone, is mixed with different amounts of cobalt naphthenate and with partial esters of phosphoric acid against green coloration. The hardening takes place afterstorage times of difierent length by the admixing of 0.2% cyclohexanone peroxide. The gel time, as well as the colours of the hardened products, are given in Table V for the mentioned polyester resins and for the resins which contain rtn'phenyl phosphine according to the invention.

12 the group consisting of triphenyl stibine, tridiphenyl stibine, trinaphthyl stibine and tritolyl stibine.

4. The polymerization mixture of claim 2 wherein the phosphine is 'a member selected from the group consisting of triphenyl phosphine, tritolyl phosphine, diphenyl phosphine, dibenzyl phosphine, dioctal phosphine, phenyl dimethyl phosphine, diethyl naphthyl phosphine, tributyl phosphine, trioctal phosphine, tris-(hydr0xyethyl)-phosphine, methylene-bis-diphenyl phosphine and tricyclepentyl phosphine, the arsine a member selected from the group consisting of triphenyl arsine, tribenzyl arsine and trioctyl arsine and the stibine a member selected from the group consisting of triphenyl stibine, tridiphenyl stibine, trinaphthyl stibine and tritolyl stibine.

Table V Triphenyl 1 Cobalt content Gel Additive for preventing greening phosphine, (introduced as Storage time Colour of the percent naphthenatc), time (min.) hardened product percent 0.0034% Phosphoric acid mono-n-butyl 0. 016 0 Bright pink.

ester 2 +0.0042% Phosphoric acid di- 24 hours- Do. n-butylester. 14 days 85 Do.

28 days 90 Do.

0.01% Phosphoric acid mono-n-butyl 0. 048 0 13 Brown-pink.

ester 2 plus 0.012% Phosphoric acid 24 hours 14 Do. di-n-butyl ester. 14 days" 19 Pink.

28 days 24 Do.

000.34% Phosphoric acid mono-n-butyl 0. 15 0. 016 0 14 Almost colourless.

ester plus 0.0042% Phosphoric acid 24 hours 12 Do. di-n-butyl ester. 14 days. 14 Bright pink.

28 days 14 Do.

0.01% Phosphoric acid mono-n-butyi 0. 11 0. 048 9 Brown-pink.

ester 2 plus 0.012% Phosphoric acid 24 hours 9 Do. di-n-butyi ester. 14 days" 10 Pink.

28 days 10 Do.

1 Mixed with the polyester resin at room temperature. 2 Added to the polyester resin together with the cobalt accelerator.

We claim:

1. A polymerization mixture which is hardenable at room temperature by the addition of a ketone peroxide polymerization initiator comprising:

(A) An unsaturated polyester prepared from an a,,8-

unsaturated dicarboxylic acid and a polyhydric alco- 1101, said polyester having an acid number below about 50 (B) A monomeric ethylenically unsaturated compound co-polymerizable therewith (C) A cobalt accelerator (D) From 0.01 to 0.1 percent by weight of a member selected from the group consisting of phosphines, arsines and stibines and (E) An acidic green-coloration inhibitor.

2. A polymerization mixture which is hardena'ble at room temperature by the addition of a ketone peroxide polymerization initiator comprising:

(A) An unsaturated polyester prepared from an (1,18- unsaturated dicarboxylic acid and a polyhydric alcohol, said polyester having an acid number above about 50 (B) A monomeric ethylenically unsaturated compound co-polymerizable therewith (C) A cobalt accelerator and (D) From 0.01 to 0.1 percent by weight of a member selected from the group consisting of phosphines, arsines and stibines.

3. The polymerization mixture of claim 1 wherein the phosphine is a member selected from the group consisting of triphenyl phosphine, tritolyl phosphine, diphenyl I phosphine, dibenzyl phosphine, dioctal phosphine, phenyl dimethyl phosphine, diethyl naphthyl phosphine, tr-ibutyl phosphine, trioctal phosphine, tris-(hydroxyethyl)-phosphine, methylene-bis-diphenyl phosphine and tricyclopentyl phosphine, the arsine a member selected from the group consisting of triphenyl-arsine, tribenzyl arsine and trioctyl arsine and the stibine a member selected from 5. The polymerization mixture of claim 1 wherein the acidic green-coloration inhibitor is a member selected from the group consisting of dipentene, organic sulfonic acids, organic carboxylic acids, partial esters of organic carboxylic acids, acidic phosphorus compounds, acidforming phosphorus compounds, acidic thiophosphorus compounds and metal salts of said acidic compounds.

6. The polymerization mixture of claim 1 wherein a phosphine is used.

7. The polymerization mixture of claim 1 wherein an arsine is used.

8. The polymerization mixture of claim 1 wherein a stibine is used.

9. Polymerization products produced from the mixtures according to claim 1.

10. Polymerization products produced from the mixtures according to claim 2.

References Cited by the Examiner UNITED STATES PATENTS 2,520,601 8/1950 Lee 26045.4 2,543,635 2/ 195 1 Loritsch 260--45 .4 2,652,382 9/1953 Davis 26045.4 3,001,967 9/1961 Willersinn 26045.4

FOREIGN PATENTS 579,190 7/ 1959 Canada.

790,940 2/ 1958 Great Britain.

822,713 10/1959 Great Britain.

OTHER REFERENCES Behnke et a1., German application, 1,130,164, printed May 24, 1962, KL 39b 22-10. 

1. A POLYMERIZATION MIXTURE WHICH IS HARDENABLE AT ROOM TEMPERATURE BY THE ADDITION OF A KETONE PEROXIDE POLYMERIZATION INITIATOR COMPRISING: (A) AN UNSATURATED POLYESTER PREPARED FROM AN A,BUNSATURATED DICARBOXYLIC ACID AND A POLYHYDRIC ALCOHOL, SAID POLYESTER HAVING AN ACID NUMBER BELOW ABOUT 50 (B) A MONOMERIC ETHYLENICALLY UNSATURATED COMPOUND CO-POLYMERIZABLE THEREWITH (C) A COBALT ACCELERATOR (D) FROM 0.01 TO 0.1 PERCENT BY WEIGHT OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF PHOSPHINES, ARSINES AND STIBINES AND (E) AN ACIDIC GREEN-COLORATION INHIBITOR.
 2. A POLYMERIZATION MIXTURE WHICH IS HARDENABLE AT ROOM TEMPERATURE BY THE ADDITION OF A KETONE PEROXIDE POLYMERIZATION INITIATOR COMPRISIN: (A) AN UNSATURATED POLYESTER PREPARED FROM AN A,BUNSATURATED DICARBOXYLIC ACID AND A POLYHYDRIC ALCOHOL, SAID POLYESTER HAVING AN ACID NUMBER ABOVE ABOUT 50 (B) A MONOMERIC ETHYLENICALLY UNSATURATED COMPOUND CO-POLYMERIZABLE THEREWIITH 8C) A COBALT ACCELERATOR AND (D) FROM 0.01 TO 0.1 PERCENT BY WEIGHT OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF PHOSPHINES, DAARSINES AND STIBINES. 